Despite support for the hypothesis that sleep loss impairs immune function, thus increasing susceptibility to infectious pathogens, human studies investigating the health outcomes associated with sleep loss are limited. This descriptive, correlational study will examine: (1) the general sleep behaviors, (2) the prevalence and frequency of sleep disturbances, and (3) the relationship between sleep disturbances and incidence of upper respiratory infections and otitis media in preschoolers attending daycare centers. Data will be collected once via a standardized sleep questionnaire and over a 12-week period using a prospective Illness Diary. The study design has proven feasible and the instruments have been pilot tested by the applicant. The results of this work will provide valuable data on the impact of sleep disturbances on the health of preschoolers attending daycare centers and may be applied to other populations also at high risk for infectious illnesses. Furthermore, this study will provide a foundation for future work developing nursing interventions to decrease the prevalence and incidence of sleep disturbances and ultimately lead to improvements in the health of children. [unreadable] [unreadable]